Walk into almost any rum shop in the Caribbean and you will see a few patrons drinking what looks like water. This liquid is most commonly downed in one gulp, after which he or she promptly drinks from another glass or bottle that does actually contain water or soda. West Indian white over-proof rum, a.k.a. strong rum, is the most popular drink in much of the Caribbean. Ask any connoisseur of such spirits and he will tell you, "It has to be hot! If it doesn't take your breath, it isn't good." But not all clear spirits will leave you gasping for your next breath.

To satisfy those consumers who want a smoother taste in a clear spirit, distillers age the rum to improve the flavor and then carbon filter it to remove any trace of color it has acquired. Carbon filtering can also remove some of the congeners or impurities, yielding a drink with less hangover potential.

So you ask, "How do I know if the rum in my glass owes its color to aging, coloring, or carbon filtering?" The only sure bets are the strongest, clear rums. If it is bottled in the Eastern Caribbean on an English-speaking island at over 50% alcohol and is clear, it is most likely a strong, hot spirit. Raw, unaged, over-proof rum straight from the still!

In the French West Indies, prior to bottling, some distilleries allow the fresh spirit to rest a few weeks or months in large oak vats, a practice called staling. You may notice a slight tint to their rhum. While the spirit will mellow considerably, staling is not considered aging. The French island distilleries don't carbon filter any of their rhum, but because their clear rhum is distilled from sugar cane juice, it lacks the sharp bite of the molasses-based rums.

In contrast, almost all the white rums bottled at a more conservative 40 to 43% alcohol content have been aged and then filtered to remove the color acquired while the spirit was mellowing in the barrel. Some distilleries bottle a white and gold version of their most popular rums. While both of these rums are aged, the one bottled as clear rum has been carbon filtered.

If the rum in your glass is very dark, you can be pretty sure that caramel has been added. But if the color is not too dark and the label doesn't say how long the rum was aged, you can only guess. When you taste and smell the rum, look for the sweet caramel traces that are sometimes present. Also, try rubbing a little dark rum vigorously between your palms and then smell your hands. You might get a clue.